Reversible top/bottom MEMS package

ABSTRACT

A semiconductor device has a base substrate having a plurality of metal traces and a plurality of base vias. An opening is formed through the base substrate. At least one die is attached to the first surface of the substrate and positioned over the opening. A cover substrate has a plurality of metal traces. A cavity in the cover substrate forms side wall sections around the cavity. The cover substrate is attached to the base substrate so the at least one die is positioned in the interior of the cavity. Ground planes in the base substrate are coupled to ground planes in the cover substrate to form an RF shield around the at least one die.

FIELD OF THE INVENTION

This invention relates to a Micro-Electro-Mechanical Systems (MEMS)package, and, more specifically, to a system and method for providing areversible top and bottom port MEMS package where the acoustic port canbe either on the bottom or on the top substrate.

BACKGROUND OF THE INVENTION

Acoustic performance in a MEMS based device requires an acoustic chamberin the package and an open port to the chamber to receive sound waveinput. MEMS devices exist where the port is either on the top or bottomof the package. The port generally points to the sound source in theOriginal Equipment Manufacturer (OEM) application. It is challenging andexpensive to align and acoustically couple the MEMS device with theinput hole in a top port application.

Bottom port MEMS devices normally have a hole in the MEMS packagesubstrate, as well as a hole in the mother board to which the MEMSdevice is mounted. Top port MEMS devices have a hole in the lid (orshield) above the MEMS device. In a top port MEMS package, either thehole is not aligned with the MEMS device and the performance suffers orthe MEMS device is coupled acoustically to the lid (or shield). Thisacoustic coupling is slow and expensive to make. Additionally, in a flipchip design, the MEMS electrical interconnect now point away from theport, making contact with the substrate. This results in a challengingprocess, due to the exposed MEMS structure, inability to under-fill, oruse wet processes for bumping.

Therefore, a need existed to provide a system and method to overcome theabove problem. The system and method will provide a reversible top andbottom port MEMS package where the port can be either on the bottom oron the top substrate.

SUMMARY OF THE INVENTION

A semiconductor device has a base substrate having a plurality of metaltraces and a plurality of base vias. An opening is formed through thebase substrate. At least one die is attached to the first surface of thesubstrate and positioned over the opening. A cover substrate has aplurality of metal traces. A cavity in the cover substrate forms sidewall sections around the cavity. The cover substrate is attached to thebase substrate so the at least one die is positioned in the interior ofthe cavity. Ground planes in the base substrate are coupled to groundplanes in the cover substrate to form an RF shield around the at leastone die.

The present invention is best understood by reference to the followingdetailed description when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of one embodiment of a MEMSpackage;

FIG. 2 is a cross-sectional side view of another embodiment of a MEMSpackage;

FIG. 3 is a cross-sectional side view of another embodiment of a MEMSpackage;

FIG. 4 is a cross-sectional side view of another embodiment of a MEMSpackage;

FIG. 5 is a cross-sectional side view of the MEMS package depicted inFIG. 1 having a multiple die design;

FIG. 6 is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 7A is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 7B is a bottom view of the cover substrate of the MEMS package ofFIG. 7A;

FIG. 8A is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 8B is a bottom view of the cover substrate of the MEMS package ofFIG. 8A;

FIG. 9A is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 9B is a transparent top view of the MEMS package of FIG. 9A;

FIG. 10A is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 10B is a bottom view of the cover substrate of the MEMS package ofFIG. 9A;

FIG. 11 is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 12 is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design;

FIG. 13 is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design; and

FIG. 14 is a cross-sectional side view of another embodiment of a MEMSpackage having a multiple die design.

Common reference numerals are used throughout the drawings and detaileddescription to indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, a cross-sectional side view of a semiconductordevice 10A (hereinafter device 10A) of the present invention is shown.The device 10A will have a base substrate 12 having an approximatelyplanar first surface and an approximately planar second surface opposingthe first surface. The base substrate 12 may be any one chosen from aconventional rigid PCB, a flexible PCB, a ceramic or an equivalentthereof, and the like, but the kind of base substrate 12 is not limitedherein.

The base substrate 12 includes an insulation layer 14 havingpredetermined area and thickness. The insulation layer 14 has anapproximately planar first surface and an approximately planar secondsurface opposing the first surface. The insulation layer 14 will haveone or more metal traces 16 formed thereon. In the embodiment shown inFIG. 1, the insulation layer 14 has metal traces 16 formed on the firstand second surface of the insulation layer 14. However, the number ofmetal traces 16 is not limited to the number shown in FIG. 1. Ingeneral, the insulation layer 14 will have multiple layers of metaltraces 16 formed therein. When multiple layers of metal traces 16 areformed in the insulation layer 14, a dielectric layer is generallyapplied between the layers of metal traces 16. The dielectric layer isused as an insulating layer to separate the layers of metal traces 16. Asoldermask may be placed over the top surface of the metal traces 16 toprotect the metal traces 16. One or more vias 18 may be formed throughthe base substrate 12. The vias 18 are generally plated or filled with aconductive material.

The semiconductor device 10A has at least one electronic component 20.In the present embodiment, a single electronic component 20 is attachedto the base substrate 12. The electronic component 20 can be atransducer, a microphone, a pressure sensor, and the like. In thepresent embodiment, the single electronic component 20 is a transducer22. However, this should not be seen as to limit the scope of thepresent invention.

The transducer 22 is placed on the first surface of the base substrate14 face down and positioned over an opening 24 formed through the basesubstrate 12. The opening 24 is an acoustic port that allows thetransducer 22 to accurately receive sound waves and convert the soundwaves to electrical signals and which provides a pressure reference forthe transducer 22.

The transducer 22 is attached to the first surface of the base substrate12. The transducer 22 may be attached to the base substrate 14 in aplurality of different manners. In the embodiment shown in FIG. 1, thetransducer 22 is attached to the substrate 14 via a wire bondingprocess. However, the above is given only as an example. The transducer22 may be attached through other technologies such as surface mounttechnology, through hole technology, flip chip technology, and the like.

The device 10A has a cover substrate 26 having an approximately planarfirst surface and an approximately planar second surface opposing thefirst surface. The cover substrate 26 may be any one chosen from aconventional rigid PCB, a flexible PCB, a ceramic or an equivalentthereof, and the like, but the kind of base substrate 12 is not limitedherein.

The cover substrate 26 includes an insulation layer 28 havingpredetermined area and thickness. The insulation layer 28 has anapproximately planar first surface and an approximately planar secondsurface opposing the first surface. The insulation layer 28 will haveone or more metal traces 30 formed thereon. In the embodiment shown inFIG. 1, the insulation layer 28 has metal traces 30 formed on the firstand second surface of the insulation layer 28. However, the number ofmetal traces 30 is not limited to the number shown in FIG. 1. Ingeneral, the insulation layer 28 will have multiple layers of metaltraces 30 formed therein. When multiple layers of metal traces 30 areformed in the insulation layer 28, a dielectric layer is generallyapplied between the layers of metal traces 30. The dielectric layer isused as an insulating layer to separate the layers of metal traces 30. Asoldermask may be placed over the top surface of the metal traces 30 toprotect the metal traces 30. One or more vias 32 may be formed throughthe cover substrate 26. The vias 32 are generally plated or filled witha conductive material.

Side sections 34 are attached to the first surface of the base substrate12 and to the second surface of the cover substrate 26. The sidesections 34 are used to support the cover substrate 26 and incombination with the cover substrate 26 form an enclosed cavity housingthe transducer 22. In accordance with the embodiment shown in FIG. 1,the side sections 34 are formed of a frame member 36. The frame member36 is generally formed of a non-conductive material. A metal plating 38may be applied on a plurality of exterior surfaces of the frame member36. The metal plating 38 of the side sections 34 are attached to metaltraces 16 and 30 on the base substrate 12 and cover substrate 26respectively. In general, a conductive material 31 is used to attach themetal plating 38 to the metal traces 16 and 30. In general, a solder, aconductive paste, or the like is used to attach the metal plating 38 tothe metal traces 16 and 30 on the base substrate 12 and cover substrate26. In accordance with one embodiment, the metal traces 16 and 30 areground planes 16A and 30A. Thus, the metal plating 38 forms a groundpathway from between the base substrate 12 and the cover substrate 26creating a Faraday cage around the transducer 22 to blocks out externalstatic electric fields. It should be noted that the ground planes 16Aand 30A may be on the first and second surfaces of the base substrate 12and the cover substrate 26. Alternatively the metal plating 38 of theside sections 34 may be attached to the ground planes 16A and 30A viaone or more of the vias 18 and 32.

One or more wirebonds 40 are used to electrically attach the transducer22 to the base substrate 12 and cover substrate 26. Each wirebond 40will have a first end attached to the transducer 22. A second end ofeach wirebond 40 is attached to a metal trace 16 formed on the firstsurface of the base substrate 12. In general, the wirebonds 40 areattached to the transducer 22 and to the metal trace 16 via bond pads.The wirebonds 40 form a loop having a height which is greater than theheight of the side sections 34.

When the cover substrate 26 is placed on the side sections 34, the topof the loops formed by the wirebonds 40 are compressed so that the topof the loops formed by the wirebonds 28 contact metal traces 30 on thesecond surface of the cover substrate 26. Thus, the active I/O run fromthe transducer 22 and/or the base substrate 12 to the cover substrate 26through the high loop wirebonds 40, which compress and maintain contactwith the metal traces 30 after assembly.

In the embodiment shown in FIG. 1, the device 10A is positioned as abottom port device. The metal traces 16 formed on the second surface ofthe base substrate 12 will generally have bond pads 42 formed thereon.The bond pads 42 will allow the second surface of the base substrate 12to be attached to an end user's board.

The device 10A may also be used as a top port device. In this case, thedevice 10A is turned over so that the opening 24 is facing upward. Thevias 32 are used as interconnects for attaching the first surface of thecover substrate 26 to the end user's board. In accordance with oneembodiment, the vias 32 are connected to pads (not shown) formed on thefirst surface of the cover substrate 26 and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

Referring to FIG. 2, another embodiment of the device 10B is shown. Thedevice 10B is similar to that shown in FIG. 1. In this embodiment, theside sections 34 are formed of a conductive interposer 52. Theconductive interposer 52 is generally a metal interposer. The conductiveinterposer 52 is attached to ground planes 16A and 30A on the basesubstrate 12 and cover substrate 26 respectively by the conductivematerial 31. In general, the conductive material is a solder, aconductive paste, or the like. In this embodiment, the conductiveinterposer 52 forms a ground pathway between the base substrate 12 andthe cover substrate 26 creating a Faraday cage around the transducer 22to blocks out external static electric fields. It should be noted thatthe ground planes 16A and 30A may be on the first and second surfaces ofthe base substrate 12 and the cover substrate 26. Alternatively theconductive interposer 52 may be attached to the ground planes 16A and30A via one of the vias 18 and 32.

Referring to FIG. 3, another embodiment of the device 10C is shown. Thedevice 10D is similar to that shown in FIG. 1. In this embodiment, theside sections 34 are formed of a conductive molding compound 54. Theconductive molding compound 54 is generally a molding compound having aplurality of thermally conductive particles to form a thermallyconductive path in the molding compound. The conductive molding compound54 is attached to ground planes 16A and 30A on the base substrate 12 andcover substrate 26 respectively by the conductive material 31. Ingeneral, the conductive material is a solder, a conductive paste, or thelike. In this embodiment, the conductive molding compound 54 forms aground pathway between the base substrate 12 and the cover substrate 26creating a Faraday cage around the transducer 22 to blocks out externalstatic electric fields. It should be noted that the ground planes 16Aand 30A may be on the first and second surfaces of the base substrate 12and the cover substrate 26. Alternatively the conductive moldingcompound 54 may be attached to the ground planes 16A and 30A via one ofthe vias 18 and 32.

Referring to FIG. 4, another embodiment of the device 10D is shown. Thedevice 10D is similar to that shown in FIG. 1. In this embodiment, theside sections 34 are formed of a frame member 36. The frame member 36 isgenerally formed of a non-conductive material. One or more vias 56 areformed in the frame member 36. The vias 56 are plated or filled with aconductive material 58. The vias 56 are generally exposed through a sawprocess during singulation of the device 10D. The frame members 36 andthe vias 56 are attached to ground planes 16A and 30A on the basesubstrate 12 and cover substrate 26 respectively by the conductivematerial 31. In general, the conductive material is a solder, aconductive paste, or the like. In this embodiment, the vias 56plated/filled with the conductive material 58 forms a ground pathwaybetween the base substrate 12 and the cover substrate 26 creating aFaraday cage around the transducer 22 to blocks out external staticelectric fields. It should be noted that the ground planes 16A and 30Amay be on the first and second surfaces of the base substrate 12 and thecover substrate 26. Alternatively the vias 56 plated/filled with theconductive material 56 may be attached to the ground planes 16A and 30Avia one of the vias 18 and 32.

Referring to FIG. 5, another embodiment of the device 10E is shown. Thedevice 10E is similar to that shown in FIG. 1. In this embodiment, thedevice 10E has two electronic components 20 attached to the firstsurface of the base substrate 12. One of the electronic components 20 isthe transducer 22. The second electronic component 20 is an amplifier44. The amplifier 44 is used to increase the strength of the signalsreceived by the transducer 22.

The transducer 22 is placed on the base substrate 12 so to be positionedover the opening 24 formed through the base substrate 12. The amplifier44 is positioned on the first surface of the base substrate 12 and nextto the transducer 22. The transducer 22 and amplifier 44 are thenelectrically attached to metal traces 16 formed on the first surface ofthe base substrate 12 and to each other. Different methods may be usedto attach and electrically couple the electronic devices to thesubstrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

The amplifier 44 is electrically attached to the metal traces 16 and 30formed on the base substrate 14 and cover substrate 26. One or morewirebonds 50 are used to electrically attach the amplifier 44 to thebase substrate 14 and cover substrate 26. Each wirebond 50 will have afirst end attached to the amplifier 44. A second end of each wirebond 50is attached to a metal trace 16 formed on the first surface of the basesubstrate 12. In general, the wirebonds 50 are attached to the amplifier44 and to the metal trace 16 via bond pads. The wirebonds 50 form a loophaving a height which is greater than the height of the side sections34.

When the cover substrate 26 is placed on the side sections 34, the topof the loops formed by the wirebonds 50 are compressed so that the topof the loops formed by the wirebonds 50 contact metal traces 30 on thecover substrate 26. Thus, the active I/O run from the amplifier 44and/or the base substrate 12 to the cover substrate 26 through the highloop wirebonds 50, which compress and maintain contact with the metaltraces 30 after assembly.

The metal plating 38 of the side sections 34 are attached to groundplanes 16A and 30A on the base substrate 12 and cover substrate 26respectively. In general, a conductive material 31 is used to attach themetal plating 38 to the ground planes 16A and 30A. Thus, the metalplating 38 forms a ground pathway from between the base substrate 12 andthe cover substrate 26 creating a Faraday cage around the transducer 22and amplifier 44 to block out external static electric fields. It shouldbe noted that the ground planes 16A and 30A may be on the first andsecond surfaces of the base substrate 12 and the cover substrate 26respectively. Alternatively the metal plating 38 of the side sections 34may be attached to the ground planes 16A and 30A via one of the vias 18and 32.

In the embodiment shown in FIG. 5, the device 10E is positioned as abottom port device. The metal traces 16 formed on the second surface ofthe base substrate 12 will generally have bond pads 42 formed thereon.The bond pads 42 will allow the second surface of the base substrate 12to be attached to an end user's board.

The device 10E may also be used as a top port device. In this case, thedevice 10B is turned over so that the opening 24 is facing upward. Thevias 32 are used as interconnects for attaching the first surface of thecover substrate 26 to the end user's board. In accordance with oneembodiment, the vias 32 are connected to pads (not shown) formed on thefirst surface of the cover substrate 26 and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

Referring to FIG. 6, another embodiment of the device 10F is shown. Thedevice 10F is similar to that shown in FIG. 5. In this embodiment, theside sections 34 are formed of a stacked solder ball structure 60. Thestacked solder ball structure 60 is generally is attached to groundplanes 16A and 30A on the base substrate 12 and cover substrate 26respectively by the conductive material 31. In this embodiment, thestacked solder ball structure 60 forms a ground pathway between the basesubstrate 12 and the cover substrate 26 creating a Faraday cage aroundthe transducer 22 and amplifier 44 to block out external static electricfields. It should be noted that the ground planes 16A and 30A may be onthe first and second surfaces of the base substrate 12 and the coversubstrate 26. Alternatively the stacked solder ball structure 60 may beattached to the ground planes 16A and 30A via one of the vias 18 and 32.

Referring to FIGS. 7A and 7B, another embodiment of the device 10G isshown. The device 10G is similar to that shown in FIG. 5. The transducer22 is placed on the base substrate 12 so to be positioned over theopening 24 formed through the base substrate 12. The amplifier 44 ispositioned on the first surface of the base substrate 12 and next to thetransducer 22. The transducer 22 and amplifier 44 are then electricallyattached to metal traces 16 formed on the first surface of the basesubstrate 12 and to each other. Different methods may be used to attachand electrically couple the electronic devices to the substrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

The amplifier 44 is electrically attached to the metal traces 16 formedon the base substrate 14. One or more wirebonds 55 are used toelectrically attach the amplifier 44 to the base substrate 14. Eachwirebond 55 will have a first end attached to the amplifier 44. A secondend of each wirebond 55 is attached to a metal trace 16 formed on thefirst surface of the base substrate 12. In general, the wirebonds 55 areattached to the amplifier 44 and to the metal trace 16 via bond pads.

In this embodiment, the side sections 34 are formed of a frame member36. The frame member 34 is generally formed of a non-conductivematerial. One or more vias 62 are formed in the frame member 34. Thevias 62 are generally not exposed. The vias 62 are plated or filled witha conductive material 64. The vias 62A around the perimeter of thedevice 10G are generally used as grounding vias. The vias 62A areattached to ground planes 16A and 30A on the base substrate 12 and coversubstrate 26 respectively by the conductive material 31. In general, theconductive material is a solder, a conductive paste, or the like. Inthis embodiment, the vias 62A plated/filled with the conductive material64 forms a ground pathway between the base substrate 12 and the coversubstrate 26 creating a Faraday cage around the transducer 22 andamplifier 44 to blocks out external static electric fields. It should benoted that the ground planes 16A and 30A may be on the first and secondsurfaces of the base substrate 12 and the cover substrate 26.Alternatively the vias 62A may be attached to the ground planes 16A and30A via one of the vias 18 and 32. As shown more clearly in FIG. 7B, theground plane 30A forms a ground ring 31 around the perimeter of thecover substrate 26.

The device 10G further has vias 62B. In the embodiment shown, the vias62B are located inside of the perimeter formed by the vias 62A. The vias62B are generally used as signal vias. The vias 62B are attached tometal traces 16 and 30 on the base substrate 12 and cover substrate 26respectively by the conductive material 31. In general, the conductivematerial is a solder, a conductive paste, or the like. In thisembodiment, the vias 62B plated/filled with the conductive material 64forms an I/O run between the base substrate 12 and cover substrate 26.

Referring to FIGS. 8A and 8B, another embodiment of the device 10H isshown. The device 10G is similar to that shown in FIG. 5. In thisembodiment, the side sections 34 are formed of a frame member 36. Theframe member 34 is generally formed of a non-conductive material. One ormore vias 66 are formed in the frame member 66. The vias 66 are platedor filled with a conductive material 68. The vias 66A around theperimeter of the device 10H are exposed. The vias 66A are exposedthrough a saw process during singulation of the device 10H. The vias 66Aare generally used as grounding vias. The vias 66A are attached toground planes 16A and 30A on the base substrate 12 and cover substrate26 respectively by the conductive material 31. In general, theconductive material is a solder, a conductive paste, or the like. Inthis embodiment, the vias 66A plated/filled with the conductive material68 forms a ground pathway between the base substrate 12 and the coversubstrate 26 creating a Faraday cage around the transducer 22 to blocksout external static electric fields. It should be noted that the groundplanes 16A and 30A may be on the first and second surfaces of the basesubstrate 12 and the cover substrate 26. Alternatively the vias 66A maybe attached to the ground planes 16A and 30A via one of the vias 18 and32. As shown more clearly in FIG. 8B, the ground plane 30A forms aground ring around the perimeter of the cover substrate 26.

The device 10H further has vias 66B. The vias 66B are generally used assignal vias. In the embodiment shown in FIGS. 8A and 8B, the vias 66Bare formed inside of the vias 66A and are not exposed. The vias 66B areattached to metal traces 16 and 30 on the base substrate 12 and coversubstrate 26 respectively by the conductive material 31. In general, theconductive material is a solder, a conductive paste, or the like. Inthis embodiment, the vias 66B plated/filled with the conductive material68 form I/O signal pathways between the base substrate 12 and the coversubstrate 26.

Referring to FIGS. 9A and 9B, another embodiment of the device 10I isshown. In this embodiment, the device 10I has two electronic components20 attached to the first surface of the base substrate 12. One of theelectronic components 20 is the transducer 22. The second electroniccomponent 20 is an amplifier 44. The amplifier 44 is used to increasethe strength of the signals received by the transducer 22.

The transducer 22 is placed on the base substrate 12 so to be positionedover the opening 24 formed through the base substrate 12. The amplifier44 is positioned on the first surface of the base substrate 12 and nextto the transducer 22. The transducer 22 and amplifier 44 are thenelectrically attached to metal traces 16 formed on the first surface ofthe base substrate 12 and to each other. Different methods may be usedto attach and electrically couple the electronic devices to thesubstrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

The amplifier 44 is electrically attached to the metal traces 16 and 30formed on the base substrate 14 and cover substrate 26. One or morewirebonds 50 are used to electrically attach the amplifier 44 to thebase substrate 14 and cover substrate 26. Each wirebond 50 will have afirst end attached to the amplifier 44. A second end of each wirebond 50is attached to a metal trace 16 formed on the first surface of the basesubstrate 12. In general, the wirebonds 50 are attached to the amplifier44 and to the metal trace 16 via bond pads. The wirebonds 50 form a loophaving a height which is greater than the height of the side sections34.

A plurality of wirebonds 70 is used to form an RF shield around thetransducer 22 and amplifier 44. Each wirebond 70 will have a first endattached to a ground plane 16A on the first surface of the basesubstrate. A second end of each wirebond 70 is attached to a groundplane 16A on the first surface of the base substrate 12. The wirebonds70 form a loop having a height which is greater than the height of theside sections 34.

When the cover substrate 26 is placed on the side sections 34, the topof the loops formed by the wirebonds 50 and 70 are compressed so thatthe top of the loops formed by the wirebonds 50 and 70 contact metaltraces 30 and ground planes 30A respectively on the cover substrate 26.Thus, the wirebonds 50 and 70 form I/O signal pathways and groundpathways respectively between the base substrate 12 and the coversubstrate 26. The wirebonds 70 create a Faraday cage around thetransducer 22 and amplifier 44 to block out external static electricfields.

As shown more clearly in FIG. 9B, the cover substrate 26 has a pluralityof vias 32. The vias 32 are generally plated or filled with a conductivematerial. The vias 32A around the perimeter of the cover substrate 26are grounded forming a ground ring around the perimeter of the coversubstrate 26. The vias 32B formed within the perimeter formed by thevias 32A are used as interconnects for attaching the first surface ofthe cover substrate 26 to the end user's board.

In this embodiment, the side sections 34 are formed of a frame member36. The frame member 34 is generally formed of a non-conductivematerial. The frame member 34 may be attached to the base substrate 12and the cover substrate 26 by an adhesive (not shown) or the like.

In the embodiment shown in FIGS. 9A and 9B, the device 10I is positionedas a bottom port device. The metal traces 16 formed on the secondsurface of the base substrate 12 will generally have bond pads 42 formedthereon. The bond pads 42 will allow the second surface of the basesubstrate 12 to be attached to an end user's board.

The device 10I may also be used as a top port device. In this case, thedevice 10I is turned over so that the opening 24 is facing upward. Thevias 32B are used as interconnects for attaching the first surface ofthe cover substrate 26 to the end user's board. In accordance with oneembodiment, the vias 32B connected to pads (not shown) formed on thefirst surface of the cover substrate 26 and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

Referring to FIGS. 10A and 10B, another embodiment of the device 10J isshown. The device 10J will have a base substrate 12 having anapproximately planar first surface and an approximately planar secondsurface opposing the first surface. The base substrate 12 includes aninsulation layer 14 having predetermined area and thickness. Theinsulation layer 14 has an approximately planar first surface and anapproximately planar second surface opposing the first surface. Theinsulation layer 14 will have one or more metal traces 16 formedthereon. In the embodiment shown in FIG. 10A, the insulation layer 14has metal traces 16 formed on the first and second surface of theinsulation layer 14. However, the number of metal traces 16 is notlimited to the number shown in FIG. 1. In general, the insulation layer14 will have multiple layers of metal traces 16 formed therein. Whenmultiple layers of metal traces 16 are formed in the insulation layer14, a dielectric layer is generally applied between the layers of metaltraces 16. The dielectric layer is used as an insulating layer toseparate the layers of metal traces 16. A soldermask may be placed overthe top surface of the metal traces 16 to protect the metal traces 16.One or more vias 18 may be formed through the base substrate 12. Thevias 18 are generally plated or filled with a conductive material. Inthe embodiment shown in FIG. 10A, the base substrate 12 does not havethe opening 24.

The semiconductor device 10J has the amplifier 44 positioned on thefirst surface of the base substrate 12. In the present embodiment, anadhesive 46 is used to attach the amplifier 44 to the base substrate 12.The adhesive may be a film, a paste or the like. The listing of theabove is given as an example and should not be seen as to limit thescope of the present invention. Wirebonds 74 are then used toelectrically connect the amplifier 44 to metal traces 16 formed on thefirst surface of the base substrate 12. Different methods may be used toelectrically attach the amplifier 44 to the metal traces 16 withoutdeparting from the spirit and scope of the present invention.

The device 10J has a cover substrate 26 having an approximately planarfirst surface and an approximately planar second surface opposing thefirst surface. The cover substrate 26 includes an insulation layer 28having predetermined area and thickness. The insulation layer 28 has anapproximately planar first surface and an approximately planar secondsurface opposing the first surface. The insulation layer 28 will haveone or more metal traces 30 formed thereon. In the embodiment shown inFIG. 10A, the insulation layer 28 has metal traces 30 formed on thefirst and second surface of the insulation layer 28. However, the numberof metal traces 30 is not limited to the number shown in FIG. 10A. Ingeneral, the insulation layer 28 will have multiple layers of metaltraces 30 formed therein. When multiple layers of metal traces 30 areformed in the insulation layer 28, a dielectric layer is generallyapplied between the layers of metal traces 30. The dielectric layer isused as an insulating layer to separate the layers of metal traces 30. Asoldermask may be placed over the top surface of the metal traces 30 toprotect the metal traces 30. One or more vias 32 may be formed throughthe cover substrate 26. The vias 32 are generally plated or filled witha conductive material. An opening 76 is formed through the basesubstrate 12.

The transducer 22 is placed on a first surface of the cover substrate26. The transducer 22 is placed on the first surface of the coversubstrate 14 face down and positioned over the opening 76 formed throughthe cover substrate 26. The opening 76 is an acoustic port that allowsthe transducer 22 to accurately receive sound waves and convert thesound waves to electrical signals and which provides a pressurereference for the transducer 22.

The transducer 22 is attached to the first surface of the coversubstrate 26. The transducer 22 is attached to the substrate 14 via awire bonding process. However, the above is given only as an example.The transducer 22 may be attached through other technologies such assurface mount technology, through hole technology, flip chip technology,and the like.

Wirebonds 80 are then used to electrically attach the transducer tometal traces 30 on the first surface of the cover substrate 26. Eachwirebond 80 will have a first end attached to the transducer 22. Asecond end of each wirebond 80 is attached to a metal trace 30 on thefirst surface of the cover substrate 26.

Side sections 34 are attached to the first surface of the base substrate12 and to the second surface of the cover substrate 26. The sidesections 34 are used to support the cover substrate 26 and incombination with the cover substrate 26 form an enclosed cavity housingthe device 10J. In the present embodiment, the side sections 34 areformed of a frame member 36. The frame member 34 is generally formed ofa non-conductive material. One or more vias 66 are formed in the framemember 66. The vias 66 are plated or filled with a conductive material68. The vias 66A around the perimeter of the device 10J are exposed. Thevias 66A are exposed through a saw process during singulation of thedevice 10H. The vias 66A are generally used as grounding vias. The vias66A are attached to ground planes 16A and 30A on the base substrate 12and cover substrate 26 respectively by the conductive material 31. Ingeneral, the conductive material is a solder, a conductive paste, or thelike. In this embodiment, the vias 66A plated/filled with the conductivematerial 68 forms a ground pathway between the base substrate 12 and thecover substrate 26 creating a Faraday cage around the transducer 22 toblocks out external static electric fields. It should be noted that theground planes 16A and 30A may be on the first and second surfaces of thebase substrate 12 and the cover substrate 26. Alternatively the vias 66Amay be attached to the ground planes 16A and 30A via one of the vias 18and 32. As shown more clearly in FIG. 8B, the ground plane 30A forms aground ring around the perimeter of the cover substrate 26.

The device 10J further has vias 66B. The vias 66B are generally used assignal vias. In the embodiment shown in FIGS. 10A and 10B, the vias 66Bare formed inside of the vias 66A and are not exposed. The vias 66B areattached to metal traces 16 and 30 on the base substrate 12 and coversubstrate 26 respectively by the conductive material 31. In general, theconductive material is a solder, a conductive paste, or the like. Inthis embodiment, the vias 66B plated/filled with the conductive material68 form I/O signal pathways between the base substrate 12 and the coversubstrate 26.

In the embodiment shown in FIGS. 10A and 10B, the device 10J ispositioned as a top port device. The metal traces 16 formed on thesecond surface of the base substrate 12 will generally have bond pads 42formed thereon. The bond pads 42 will allow the second surface of thebase substrate 12 to be attached to an end user's board.

The device 10J may also be used as a bottom port device. In this case,the device 10J is turned over so that the opening 76 is facing downward.The vias 32 are used as interconnects for attaching the first surface ofthe cover substrate 26 to the end user's board. In accordance with oneembodiment, the vias 32 are connected to pads (not shown) formed on thefirst surface of the cover substrate 26 and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

Referring to FIG. 11, another embodiment of the device 10K is shown. Thedevice 10K is similar to that shown in FIG. 7. The transducer 22 isplaced on the base substrate 12 so to be positioned over the opening 24formed through the base substrate 12. The amplifier 44 is positioned onthe first surface of the base substrate 12 and next to the transducer22. The transducer 22 and amplifier 44 are then electrically attached tometal traces 16 formed on the first surface of the base substrate 12 andto each other. Different methods may be used to attach and electricallycouple the electronic devices to the substrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

The amplifier 44 is electrically attached to the metal traces 16 formedon the base substrate 14. One or more wirebonds 55 are used toelectrically attach the amplifier 44 to the base substrate 14. Eachwirebond 55 will have a first end attached to the amplifier 44. A secondend of each wirebond 55 is attached to a metal trace 16 formed on thefirst surface of the base substrate 12. In general, the wirebonds 55 areattached to the amplifier 44 and to the metal trace 16 via bond pads.

In this embodiment, the cover substrate 26A has a cavity 26B formedtherein. The cavity 26B forms side wall sections 34A. The coversubstrate 26A is positioned over and attached to the base substrate 12so that the transducer 22 and amplifier 44 are positioned in theinterior of the cavity 26B. The side wall sections 34A are attached tothe first surface of the base substrate 12. In general, an adhesive isused to attach the side wall sections 34A to the base substrate 12. Inaccordance with one embodiment, the side wall sections 34A are attachedto metal traces 16A on the first surface of the base substrate 12. Aconductive material 31 is used to attach the side wall sections 34A tothe metal traces 16.

One or more vias 62 are formed in the side wall sections 34A of thecover substrate 26A. The vias 62 are generally not exposed. The vias 62are plated or filled with a conductive material 64. The vias 62A aroundthe perimeter of the device 10K are generally used as grounding vias.The vias 62A are attached to ground planes 16A on the base substrate 12by the conductive material 31. In general, the conductive material 31 isa solder, a conductive paste, or the like. The vias 62A are furthercoupled to ground planes 30A formed in the cover substrate 26A. In thisembodiment, the vias 62A plated/filled with the conductive material 64forms a ground pathway between the base substrate 12 and the coversubstrate 26A creating a Faraday cage around the transducer 22 andamplifier 44 to blocks out external static electric fields. The groundplane 30A forms a ground ring 31 around the perimeter of the coversubstrate 26A.

The device 10K may further have vias 62B. In the embodiment shown, thevias 62B are located inside of the perimeter formed by the vias 62A. Thevias 62B are generally used as signal vias. The vias 62B are attached tometal traces 16 and 30 on the base substrate 12 and cover substrate 26A.The vias 62B are attached to metal traces 16 on the base substrate 12 bythe conductive material 31. The vias 62A are further coupled to metaltraces 30 formed in the cover substrate 26A. In this embodiment, thevias 62B plated/filled with the conductive material 64 forms an I/O runbetween the base substrate 12 and cover substrate 26A.

Referring to FIG. 12, another embodiment of the device 10L is shown. Thedevice 10L is similar to that shown in FIG. 8. The transducer 22 isplaced on the base substrate 12 so to be positioned over the opening 24formed through the base substrate 12. The amplifier 44 is positioned onthe first surface of the base substrate 12 and next to the transducer22. The transducer 22 and amplifier 44 are then electrically attached tometal traces 16 formed on the first surface of the base substrate 12 andto each other. Different methods may be used to attach and electricallycouple the electronic devices to the substrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

The amplifier 44 is electrically attached to the metal traces 16 formedon the base substrate 14. One or more wirebonds 55 are used toelectrically attach the amplifier 44 to the base substrate 14. Eachwirebond 55 will have a first end attached to the amplifier 44. A secondend of each wirebond 55 is attached to a metal trace 16 formed on thefirst surface of the base substrate 12. In general, the wirebonds 55 areattached to the amplifier 44 and to the metal trace 16 via bond pads.

In this embodiment, the cover substrate 26A has a cavity 26B formedtherein. The cavity 26B forms side wall sections 34A. The coversubstrate 26A is positioned over and attached to the base substrate 12so that the transducer 22 and amplifier 44 are positioned in theinterior of the cavity 26B. The side wall sections 34A are attached tothe first surface of the base substrate 12. In general, an adhesive isused to attach the side wall sections 34A to the base substrate 12. Inaccordance with one embodiment, the side wall sections 34A are attachedto metal traces 16A on the first surface of the base substrate 12. Aconductive material 31 is used to attach the side wall sections 34A tothe metal traces 16.

One or more vias 66 are formed in the side wall section 34A of the coversubstrate 26A. The vias 66 are plated or filled with a conductivematerial 68. The vias 66A around the perimeter of the device 10L areexposed. The vias 66A are exposed through a saw process duringsingulation of the device 10L. The vias 66A are generally used asgrounding vias. The vias 66A are attached to ground planes 16A and 30Aon the base substrate 12 and cover substrate 26A. The vias 66A areattached to ground planes 16A on the base substrate 12 by the conductivematerial 31 and to the ground planes 30A via the conductive material 68.The vias 66A plated/filled with the conductive material 68 forms aground pathway between the base substrate 12 and the cover substrate 26Acreating a Faraday cage around the transducer 22 to blocks out externalstatic electric fields. The ground plane 30A forms a ground ring aroundthe perimeter of the cover substrate 26A.

The device 10L further has vias 66B. The vias 66B are generally used assignal vias. In the embodiment shown in FIG. 12, the vias 66B are formedinside of the vias 66A and are not exposed. The vias 66B are attached tometal traces 16 on the base substrate 12 by the conductive material 31and to the metal traces 30 via the conductive material 68. In thisembodiment, the vias 66B plated/filled with the conductive material 68form I/O signal pathways between the base substrate 12 and the coversubstrate 26A.

Referring to FIG. 13, another embodiment of the device 10M is shown. Thedevice 10I is similar to that shown in FIG. 9. The transducer 22 isplaced on the base substrate 12 so to be positioned over the opening 24formed through the base substrate 12. The amplifier 44 is positioned onthe first surface of the base substrate 12 and next to the transducer22. The transducer 22 and amplifier 44 are then electrically attached tometal traces 16 formed on the first surface of the base substrate 12 andto each other. Different methods may be used to attach and electricallycouple the electronic devices to the substrate 14.

In the present embodiment, an adhesive 46 is used to attach theamplifier 44 to the base substrate 12. The adhesive may be a film, apaste or the like. The listing of the above is given as an example andshould not be seen as to limit the scope of the present invention.Wirebonds 48 are then used to electrically connect the amplifier 44 tothe transducer 22. The transducer 22 is attached to the base substrate14 via a wire bonding process. However, the above is given only as anexample. Other technology may be used to electrically couple theelectronic devices without departing from the spirit and scope of theinvention.

In this embodiment, the cover substrate 26A has a cavity 26B formedtherein. The cavity 26B forms side wall sections 34A. The coversubstrate 26A is positioned over and attached to the base substrate 12so that the transducer 22 and amplifier 44 are positioned in theinterior of the cavity 26B. The side wall sections 34A are attached tothe first surface of the base substrate 12. In general, an adhesive isused to attach the side wall sections 34A to the base substrate 12. Inaccordance with one embodiment, the side wall sections 34A are attachedto metal traces 16A on the first surface of the base substrate 12. Aconductive material 31 is used to attach the side wall sections 34A tothe metal traces 16.

The amplifier 44 is electrically attached to the metal traces 16 and 30formed on the base substrate 14 and cover substrate 26A. One or morewirebonds 50 are used to electrically attach the amplifier 44 to thebase substrate 14 and cover substrate 26A. Each wirebond 50 will have afirst end attached to the amplifier 44. A second end of each wirebond 50is attached to a metal trace 16 formed on the first surface of the basesubstrate 12. In general, the wirebonds 50 are attached to the amplifier44 and to the metal trace 16 via bond pads. The wirebonds 50 form a loophaving a height which is greater than the height of the side wallsections 34A.

A plurality of wirebonds 70 is used to form an RF shield around thetransducer 22 and amplifier 44. Each wirebond 70 will have a first endattached to a ground plane 16A on the first surface of the basesubstrate. A second end of each wirebond 70 is attached to a groundplane 16A on the first surface of the base substrate 12. The wirebonds70 form a loop having a height which is greater than the height of theside wall sections 34A.

When the cover substrate 26A is positioned over and attached to the basesubstrate 12 so that the transducer 22 and amplifier 44 are positionedin the interior of the cavity 26B, the top of the loops formed by thewirebonds 50 and 70 are compressed so that the top of the loops formedby the wirebonds 50 and 70 contact metal traces 30 and ground planes 30Arespectively on the cover substrate 26A. Thus, the wirebonds 50 and 70form I/O signal pathways and ground pathways respectively between thebase substrate 12 and the cover substrate 26A. The wirebonds 70 create aFaraday cage around the transducer 22 and amplifier 44 to block outexternal static electric fields.

The cover substrate 26 may have a plurality of vias 32. The vias 32 aregenerally plated or filled with a conductive material. The vias 32Aaround the perimeter of the cover substrate 26 are grounded forming aground ring around the perimeter of the cover substrate 26. The vias 32Bformed within the perimeter formed by the vias 32A are used asinterconnects for attaching the first surface of the cover substrate 26to the end user's board.

In the embodiment shown in FIG. 13, the device 10M is positioned as abottom port device. The metal traces 16 formed on the second surface ofthe base substrate 12 will generally have bond pads 42 formed thereon.The bond pads 42 will allow the second surface of the base substrate 12to be attached to an end user's board.

The device 10M may also be used as a top port device. In this case, thedevice 10M is turned over so that the opening 24 is facing upward. Thevias 32B are used as interconnects for attaching the first surface ofthe cover substrate 26A to the end user's board. In accordance with oneembodiment, the vias 32B connected to pads (not shown) formed on thefirst surface of the cover substrate 26A and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

Referring to FIG. 14, another embodiment of the device 1 ON is shown.The device 10N will have a base substrate 12 having an approximatelyplanar first surface and an approximately planar second surface opposingthe first surface. The base substrate 12 includes an insulation layer 14having predetermined area and thickness. The insulation layer 14 has anapproximately planar first surface and an approximately planar secondsurface opposing the first surface. The insulation layer 14 will haveone or more metal traces 16 formed thereon. In the embodiment shown inFIG. 14, the insulation layer 14 has metal traces 16 formed on the firstand second surface of the insulation layer 14. However, the number ofmetal traces 16 is not limited to the number shown in FIG. 14. Ingeneral, the insulation layer 14 will have multiple layers of metaltraces 16 formed therein. When multiple layers of metal traces 16 areformed in the insulation layer 14, a dielectric layer is generallyapplied between the layers of metal traces 16. The dielectric layer isused as an insulating layer to separate the layers of metal traces 16. Asoldermask may be placed over the top surface of the metal traces 16 toprotect the metal traces 16. One or more vias 18 may be formed throughthe base substrate 12. The vias 18 are generally plated or filled with aconductive material. In the embodiment shown in FIG. 14, the basesubstrate 12 does not have the opening 24.

The amplifier 44 is positioned on the first surface of the basesubstrate 12. In the present embodiment, an adhesive 46 is used toattach the amplifier 44 to the base substrate 12. The adhesive may be afilm, a paste or the like. The listing of the above is given as anexample and should not be seen as to limit the scope of the presentinvention. Wirebonds 74 are then used to electrically connect theamplifier 44 to metal traces 16 formed on the first surface of the basesubstrate 12. Different methods may be used to electrically attach theamplifier 44 to the metal traces 16 without departing from the spiritand scope of the present invention.

The semiconductor device 10N has a cover substrate 26A. The coversubstrate 26A has a cavity 26B formed therein. The cavity 26B forms sidewall sections 34A. The cover substrate 26A has an insulation layer 28having predetermined area and thickness. The insulation layer 28 willhave one or more metal traces 30 formed thereon. The number of metaltraces 30 is not limited to the number shown in FIG. 14. In general, theinsulation layer 28 will have multiple layers of metal traces 30 formedtherein. When multiple layers of metal traces 30 are formed in theinsulation layer 28, a dielectric layer is generally applied between thelayers of metal traces 30. The dielectric layer is used as an insulatinglayer to separate the layers of metal traces 30. A soldermask may beplaced over the top surface of the metal traces 30 to protect the metaltraces 30. One or more vias 32 may be formed through the side wallsections 26A of the cover substrate 26. The vias 32 are generally platedor filled with a conductive material. An opening 76 is formed throughthe cover substrate 26A.

The transducer 22 is placed on a first surface of the cover substrate26A in the interior of the cavity 26B. The transducer 22 is placed onthe first surface of the cover substrate 26A face down and positionedover the opening 76 formed through the cover substrate 26A. The opening76 is an acoustic port that allows the transducer 22 to accuratelyreceive sound waves and convert the sound waves to electrical signalsand which provides a pressure reference for the transducer 22.

The transducer 22 is electrically coupled to the first surface of thecover substrate 26A. The transducer 22 is attached to the substrate 14via a wire bonding process. However, the above is given only as anexample. The transducer 22 may be attached through other technologiessuch as surface mount technology, through hole technology, flip chiptechnology, and the like.

Wirebonds 80 are then used to electrically attach the transducer tometal traces 30 on the first surface of the cover substrate 26A. Eachwirebond 80 will have a first end attached to the transducer 22. Asecond end of each wirebond 80 is attached to a metal trace 30 on thefirst surface of the cover substrate 26A.

Side wall sections 34A are attached to the first surface of the basesubstrate 12. In general, an adhesive is used to attach the side wallsections 34A to the base substrate 12. In accordance with oneembodiment, the side wall sections 34A are attached to metal traces 16Aon the first surface of the base substrate 12. A conductive material 31is used to attach the side wall sections 34A to the metal traces 16.

One or more vias 66 are formed in the frame member 66. The vias 66 areplated or filled with a conductive material 68. The vias 66A around theperimeter of the device 10N are exposed. The vias 66A are exposedthrough a saw process during singulation of the device 10N. The vias 66Aare generally used as grounding vias. The vias 66A are attached toground planes 16A on the base substrate 12 by the conductive material 31and to the ground planes 30A on the cover substrate 26A by theconductive material 68 in the vias 66A. In this embodiment, the vias 66Aplated/filled with the conductive material 68 forms a ground pathwaybetween the base substrate 12 and the cover substrate 26 creating aFaraday cage around the transducer 22 to blocks out external staticelectric fields. The ground plane 30A forms a ground ring around theperimeter of the cover substrate 26.

The device 10N further has vias 66B. The vias 66B are generally used assignal vias. In the embodiment shown in FIG. 14, the vias 66B are formedinside of the vias 66A and are not exposed. The vias 66B are attached tometal traces 16 and 30 on the base substrate 12 and cover substrate 26respectively. The vias 66B are attached to metal traces 16 on the basesubstrate 12 by the conductive material 31 and to the metal traces 30 onthe cover substrate 26A by the conductive material 68 in the vias 66A.In this embodiment, the vias 66B plated/filled with the conductivematerial 68 form I/O signal pathways between the base substrate 12 andthe cover substrate 26.

In the embodiment shown in FIG. 14, the device 10N is positioned as atop port device. The metal traces 16 formed on the second surface of thebase substrate 12 will generally have bond pads 42 formed thereon. Thebond pads 42 will allow the second surface of the base substrate 12 tobe attached to an end user's board.

The device 10N may also be used as a bottom port device. In this case,the device 10N is turned over so that the opening 76 is facing downward.The vias 32 are used as interconnects for attaching the first surface ofthe cover substrate 26 to the end user's board. In accordance with oneembodiment, the vias 32 are connected to pads (not shown) formed on thefirst surface of the cover substrate 26 and the pads are used as LandGrid Array (LGA) solder interconnects wherein a solder paste is applieddirectly between the pads and the end user's board.

This disclosure provides exemplary embodiments of the present invention.The scope of the present invention is not limited by these exemplaryembodiments. Numerous variations, whether explicitly provided for by thespecification or implied by the specification, such as variations instructure, dimension, type of material and manufacturing process may beimplemented by one of skill in the art in view of this disclosure.

What is claimed is:
 1. A semiconductor device comprising: a basesubstrate having a plurality of metal traces and a plurality of basevias; an opening formed through the base substrate; at least one dieattached to the first surface of the substrate and positioned over theopening, the opening allowing the at least one die to receive soundwaves; a cover substrate having a plurality of metal traces, a cavity inthe cover substrate forming side wall sections around the cavity, thecover substrate attached to the base substrate wherein the at least onedie is positioned in the interior of the cavity; and ground vias formedin the side wall sections to couple the ground planes in the basesubstrate to ground planes in the cover substrate to form an RF shieldaround the at least one die; wherein side sections of the ground viasare exposed.
 2. A semiconductor device in accordance with claim 1,further comprising signal vias formed in the side wall sections andcoupled to metal traces in the base substrate and cover substrate.
 3. Asemiconductor device in accordance with claim 2, wherein the conductivesignal vias are formed along an inner perimeter of the side wall membersand the conductive ground vias are formed along an outer perimeter ofthe side wall members.
 4. A semiconductor device in accordance withclaim 1, further comprising a plurality of wires, wherein each wire hasa first end attached to the ground plane on the base substrate and asecond end attached to the ground plane on the base substrate, each ofthe wires forming a loop wherein a top section of each loop contacts theground plane of the cover substrate.
 5. A semiconductor device inaccordance with claim 1, further comprising a plurality of cover viasformed in the cover substrate, wherein at least one of the cover viasconnected to a plurality of pads when the cover substrate is attached toan I/O board.
 6. A semiconductor device comprising: a base substratehaving a plurality of metal traces and a plurality of base vias; anopening formed through the base substrate; a first electronic componentattached to the first surface of the base substrate and positioned overthe opening, the opening allowing the first electronic device to receivesound waves; a second electronic component attached to the first surfaceof the base substrate next to the first electronic component; a firstset of wirebonds to couple the first electronic component to the secondelectronic component; a cover substrate having a plurality of metaltraces, a plurality of cover vias, a cavity in the cover substrateforming side wall sections around the cavity, the cover substrateattached to the base substrate wherein the first and second electroniccomponents are positioned in the interior of the cavity; and a pluralityof grounding vias formed in the sidewall for coupling ground planes inthe base substrate to ground planes in the cover substrate to form an RFshield around the first and second electronic components; wherein sidesections of the ground vias are exposed.
 7. A semiconductor device inaccordance with claim 6 further comprising means coupled to the metaltraces on the base substrate and the metal traces on the cover substrateto form I/O pathways between the base substrate and cover substrate. 8.A semiconductor device in accordance with claim 6, further comprising asecond set of wirebonds, wherein each of the second set of wirebonds hasa first end attached to the ground plane on the base substrate and asecond end attached to the ground plane on the base substrate forming aloop wherein a top section of each loop contacts the ground plane of thecover substrate.
 9. A semiconductor device in accordance with claim 7,wherein the means coupled to the metal traces on the base substrate andthe metal traces on the cover substrate to form I/O pathways between thebase substrate and cover substrate are signal vias formed in the sidewall sections.
 10. A semiconductor device in accordance with claim 7,wherein the means coupled to the metal traces on the base substrate andthe metal traces on the cover substrate to form I/O pathways comprises athird set of wirebonds, wherein each of the third set of wirebonds havea first end attached to the second electronic component and a second endattached to the metal trace of the base substrate, each of the third setof wirebonds forming a loop wherein a top section of each loop contactsthe metal traces of the cover substrate.
 11. A semiconductor device inaccordance with claim 7, wherein the ground vias formed in the side wallsections and the means coupled to the metal traces on the base substrateand the metal traces on the cover substrate to form I/O pathways betweenthe base substrate and cover substrate are signal vias formed in theside wall sections, wherein the signal vias are formed along an innerperimeter of the side wall members and the ground vias are formed alongan outer perimeter of the side wall members.
 12. A semiconductor devicecomprising: a base substrate having a plurality of metal traces, aplurality of base vias, and a plurality of base pads; a cover substratehaving a plurality of metal traces, a plurality of cover vias, and aplurality of cover pads; a cover substrate having a plurality of metaltraces, a plurality of cover vias, and a plurality of cover pads, acavity in the cover substrate forming side wall sections around thecavity; an opening formed through the cover substrate into the cavity; afirst die attached to the first surface of the cover substrate in thecavity and positioned over the opening and electrically attach to themetal traces of the cover substrate, the opening allowing the first dieto receive sound waves; a second die attached to the first surface ofthe base substrate and electrically attach to the metal traces of thebase substrate; pathways formed in the side wall sections to coupleground planes in the base substrate with ground planes in the coversubstrate to form an RF shield around the first die and the second die,wherein the pathways are conductive vias; and means coupled to the metaltraces on the base substrate and the metal traces on the cover substrateto form I/O pathways between the base substrate and cover substrate;wherein the conductive vias have exposed sides.
 13. A semiconductordevice in accordance with claim 12, wherein the means coupled to themetal traces on the base substrate and the metal traces on the coversubstrate to form I/O pathways between the base substrate and coversubstrate are signal vias formed in the side wall sections.
 14. Asemiconductor device in accordance with claim 12, wherein the meanscoupled to the metal traces on the base substrate and the metal traceson the cover substrate to form I/O pathways between the base substrateand cover substrate are signal vias formed in the side wall sections,wherein the signal vias are formed along an inner perimeter of the sidewall members and the ground vias are formed along an outer perimeter ofthe side wall members.